Note: Descriptions are shown in the official language in which they were submitted.
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Title
ELECTRIC VE~ICLE P~HP ISOLATION MOUNT
Field of Invention
The mounting of electric vehicle pumps in vehicle
fuel tanks to reduce noise and vibration reaching passenger
compartments.
Backqround and Features of the Invention
Since the advent of fuel injection systems, it has
become almostuniversal to utilize electric fuel pumps to furnish
fuel to internal combustion engines of automotive vehicles.
This system has supplanted the old system of drawing fuel from
a tank with a vacuum system or a fuel pump driven in the engine
compartment. However, since the fuel tank is usually mounted
at the rear of a vehicle below the rear passenger compartment
it has become an objective to minimize, as much as possible,
the noise and vibration resulting from the rotating, positive-
displacement pumps often used for this purpose. This effort
has resulted in pump design to reduce flashback noise. It has
also resulted in efforts to mount the pump in such a way as to
isolate noise and vibration.
In some instances a canister, that is, a small
container is mounted in a fuel tank to receive fuel return from
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a pressure regulator in the pumping circuit or from an aspirator
system. In this arrangement the pump is mounted in the canister,
usually parallel to the axis of the canister, and draws fuel
from the bottom of the canister to deliver to an outlet conduit
leading to the engine fuel supply. One example of a noise
reduction structure is found in a U.S. patent to Tuckey, No.
4,780,063 (1988) where a ribbed pliable jacket is used to
surround and mount the pump. Another example is illustrated in
a copending United States application of Hoover and Talaski,
Ser. No. 284,996, filed December 16, 1988, where metal coil
springs mount a pump housing within a jacket which is supported
on a fuel return pipe projection within a fuel tank. This
return pipe can be in a fuel tank canister or the pump may be
mounted in a baffle system in the tank, or in the tank itself.
The present inventionapproachestheisolationproblem
in terms of a cage unit which surrounds a pump housing, the
cage unit having a mounting means to receive support within a
fuel tank on a fuel return pipe, or baffle, or tank flange.
The walls of the generally cylindrical unit are provided with
leaf spring elements to bear against the side and end walls of
the pump body to suspend it resiliently, axially and radially,
in the cage unit. While it is not essential to the principles
of operations, the forming of the spring elements as strike~
outs from the side and end walls of the cylindrical unit reduces
the cost of the unit and provides a good life span as well as
permitting ready removal of the pump for repair or replacement.
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Summary of Invention
The objects of the invention are achieved by providing
a cage unit in a fuel tank which surrounds a pump housing. The
cage unit is a cylindrical container having walls with axial
and radial dimensions greater than those of the pump. Leaf
springs on the walls of the container suspend the pump in
isolation within the container. The springs can be formed from
strike outs in the walls of the container and from strike outs
in inturned flanges at theends of the container. The cylindrical
container is preferably provided with a side element to receive
support from a utility pipe depending in the basic fuel tank.
Objects and features of the invention will be apparent
inthe following specification and claims in which the principles
of the invention are set forth together with details to enable
persons skilled in the art to practice the invention, all in
connection with the best mode presently contemplated for the
invention. -
Brief Dencription of the Drawings
-
DRAWINGS accompany the disclosure and the various
views thereof may be briefly described as~
FIG. 1, a perspective view of one embodiment of the ~ ;
cage unit.
FIG. 2, a sectional view of the cage unit enclosing
a pump unit.
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FIG. 3, a sectional view on line 3--3 of FIG. 2.
FIG. 4, a sectional view on line 4--4 of FIG. 2
FIG. 5, a perspective view of a modified suspension
cage unit. ~ -
FIG. 6, a sectional view of the unit illustrated in
FIG. 1.
PIGS. 7, 8and 9, sectional views of FIG. 6respectively ;
on lines 7--7, 8--8 and 9--9 of FIG. 6. ~ ~
FIG. 10, a perspective view of a second modification. ~; ;
FIG. 11, an end view of the unit illustratedinFIG. 10.
FIG. 12, a sectional view on line 12--12 of FIG. 11.
FIG. 13, a side view of one part of the unit illustrated
in FIG. 10. ;~
Detailed Description of the Invention ~-~
and the Hanner and Process of Usina It
With reference to FIG. 2 of the drawings, an electric
fuel pump of relatively standard construction has a cylindrical
housing 2G with end walls 22 and 24 and a bottom inlet 26
connected to a filter sack 28 which rests on the bottom of a
fuel tank. A pump outlet 30 leads to a fuel conduit 32 connected
to a carburetor or a fuel injection manifold.
A support cage unit or open jacket orpod 40 illustrated
in FIGS. 1 and 2 comprises a cylindrical enclosure open at each
end and supported on a pipe 42 depending into the fuel tank
which is not shown. The pipe 42 can be a fuel return pipe
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mounted in the top of the fuel tank, or the mount may be on a
flange, or baffle in the tank.
The jacket 40 is preferably a molded plastic container
having a bottom inturned flange 44 and top inturned flange 46.
The opening 48 at the top is large enough to receive a pump 40
for insertion and positioning. The bottom flange 44 has a
greater radial dimension with an opening 49 and is formed with
arcuate slots 50 which extend around the flange about 120 to
provide resilient leaf springs 52 with root ends integral with
the jacket and on the ends of which are upright pins 54 which
will contact the bottom end wall 24 of the pump housing to
provide a resilient axial support for the pump.
The cylindrical side wall 60 of the jacket 40 is
apertured axially at longitudinal openings 62 and strike-out
tabs 64 are integral at root and top ends 66 and shaped inwardly
and outwardly to provide contact surfaces 68 which will press
resiliently against the outer walls of a pump housing to locate
it centrally within the jacket 40. Examples of a suitable
material from which to form the cage units are an Acetal plastic,
stainless steel, or a steel material with a coating to resist
deterioration from contact with hydrocarbons.
,:
The housing 40 has formed integrally therewith a side
projection 80 with a slot 82 to receive a support pipe 42 clamped
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in place by a plate 84 and screws 86. Other clamping
configurations can be used for baffles or tan~ flanges. ; ~ ;
Thus, the pump housing 20 can be lowered into the
cage 40 against the resilience of the tabs or leaf springs 64
and will be resiliently suspended axially in the cage on supports
52,54.
In FIGS. 5 to 9, a modified cage unit is illustrated
composed of bottom and top housings 90 and 92 telescoped together
at a central joint 94. Bottom and top flanges 94,96 are each ~ - -
provided with arcuate openings 98 which form resilient leaf
tabs 100 with axially extending pins 102. ;~
Each section of the housing is provided strike-out -
leaf springs 104 without proximal ends integral with the housing
wall and each digital end with an inturned tab 106. The leaf
~prings 104 are circumferentially staggered (FIG. 8) in the top
and bottom units. Each section has an outward extension 110 with
a recess 112 to receive a support pipe 114 held in place by a
clamp plate 116. In this embodiment the leaf springs 100 and
104 are resilient due to the inherent nature of the material
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from which the housingsare formed. While plastic is a preferable
material, other materials such as metal could be used. Plastic
will have a better sound absorption characteristic and provide
a resilient suspension for the pump housing 20. `~
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In FIGS . 10 to 12, a second modification is
illustrated, As in FIG. 5, two housings 120, 122 are joined in
a telescoping joint 124. Each housing has an inturned flange
126 at the open ends and three strike-in leaves 130 each with
an inturned tab end 132. The tabs 132 on the resilient leaf
springs 130 capture the pump housing 20, axially and radially
to suspend it within the housings. Spaced side projections 140
are provided to mount the cage appropriately in a gas tank or
canister.
In each of the embodiments, the cage or jacket units
are preferably formed from a material which has sound deadening
characteristics as well as inherent resilience so the supporting
leafs with root ends integrally formed in the walls of the
housings will support the pump housing axially and radially and
absorb vibration and torsional motion without transmitting it
to the supporting tank. In each embodiment the pump is spaced
axially and radially from the interior walls of the enclosing
cage.
